Games like CastleOn
Games like CastleOn include Stronghold Crusader HD (2012), Manor Lords, Frostpunk, Farthest Frontier, and Against the Storm. We matched them by the tags players give CastleOn on Steam (City Builder, Military, Colony Sim, War, and Resource Management): closest matches first, and among equally close ones the better-known games.
Stronghold Crusader HD (2012)
Shared: City Builder · Military · Colony Sim
Manor Lords
Shared: City Builder · Strategy · Base Building
Frostpunk
Shared: City Builder · Resource Management · Colony Sim
Farthest Frontier
Shared: City Builder · Resource Management · Medieval
Against the Storm
Shared: City Builder · Strategy · Base Building
Banished
Shared: City Builder · Colony Sim · Strategy
Kingdoms and Castles
Shared: City Builder · Colony Sim · Resource Management
Stronghold Crusader: Definitive Edition
Shared: City Builder · Colony Sim · Strategy
Age of Empires III: Definitive Edition
Shared: Military · City Builder · Base Building
Prison Architect
Shared: Colony Sim · City Builder · Base Building
Foundation
Shared: City Builder · Medieval · Resource Management
Oxygen Not Included
Shared: Colony Sim · Resource Management · Base Building
Becastled
Shared: City Builder · Base Building · Medieval
Workers & Resources: Soviet Republic
Shared: City Builder · Strategy · Base Building
Empires of the Undergrowth
Shared: City Builder · Colony Sim · Strategy
Stronghold: Warlords
Shared: City Builder · Colony Sim · Military
Stronghold 2: Steam Edition
Shared: City Builder · Colony Sim · Medieval
Ostriv
Shared: City Builder · Colony Sim · Strategy
Norland
Shared: City Builder · Colony Sim · Strategy
Life is Feudal: Forest Village
Shared: City Builder · Colony Sim · Resource Management
Cities: Skylines
Shared: City Builder · Building · Strategy
Stronghold: Definitive Edition
Shared: City Builder · Medieval · Strategy
Sid Meier's Civilization VII
Shared: City Builder · Military · Strategy
They Are Billions
Shared: Colony Sim · Base Building · City Builder